VFO TRICKS

My Variable Frequency Oscillator is the High Plains Drifter! Are you getting comments like "you are 1 Hz off according to my SDR"? Building an old fashioned analog VFO is an exercise in understanding the secrets of basic oscillator stability.

[@jagmarc]

This takes me back to 1980 I built a 3.5 to 4.0 MHz VFO. I also opted for JFET in Colpitts. I was lucky to have the best components and a good source of used mil standard parts. There's no substitute for getting your hands dirty and building and testing and seeing what works best

[@buckbrown823]

Another all out detailed effort to cover every component in these circuits. I appreciate how everything is explained and makes sense.

[@Steve-GM0HUU]

👍Thanks for video. Some excellent advice.

[@khalidtarawneh2289]

Alright Mike, You've hit the jackpot there AGAIN,

[@acestudioscouk-Ace-G0ACE]

There is so much to think about here...thanks for the talk through.

[@RyanFurrier]

Your channel is great, lots of cool information. Good luck with your further work!

[@vincei4252]

Thanks for the book recommendation! Snagged a copy!!

[@russpeck1320]

Great job, Mike, this looks like a book I need to get! I'm determined to get my old Atlas 210 stabilized (never stops drifting upward) without changing out the vfo (more fun this way😊), but it flunks on many of the important design elements that you mention...wish me luck!

[@accountant1653]

Большое Вам спасибо за очень интересное видео!

[@kittony71]

Thanks for video❤❤❤❤❤❤❤❤

[@Dazzwidd]

Here's a circuit topology which could make a very good VFO circuit should it be applied properly. Of course experimentation will be the key.

[@radiotec76]

Thanks for this presentation. I need several VFOs badly. I need one capable of delivering about 22 volts to the 6GK6 grid oscillator circuit of a CW transmitter I completed 36 years ago, a Johnson Viking Adventurer and a lower voltage vfo for the Tuna Tin II I homebrewed 33 years ago almost completely from Radio Shack parts. Should be fun.

[@clytle374]

Thanks for another educational video. Funny how varactors showed themselves twice in my last 24 hours. Surprised no mention of using audio taper pot on one to try to straighten it out, but sometimes to curves are worse than one to deal with.

[@Homer19521]

NPzero NP0. Great vid. First time I saw a vid on this. I'll send it to the guys who designed my drifty TS-830S.

[@umakanthbojanapalli3240]

Thanks for your valuable information

[@daviddavidson1372]

Got a couple of his books.great video..

[@Mold0vanin]

Замечательно. Интересная конструкция.

[@Travis141123]

I changed the LO caps in my old DX-160 with NP0 type. Cut the drift in half. I can actually listen to SSB with no hands now...

[@DAVIDGREGORYKERR]

What about using a Tung-Sol 12K5 12V tube that was for use in car radios when the first solid state transistors were not up to standard.

[@PapasDino]

Question - are they NPO or NP0 capacitors? Maybe their identified both ways but I always thought the temp caps were NP0 and C0G? Or is it six of one and half a dozen of the other? ;-)